Let's make it an expression.
Three half's= 3/2 Plus= + one fifth= 1/5
We need to turn 3/2 and 1/5 so that they have the same denominator. Let's use 10.
3/2→15/10 1/5→2/10
15/10+2/10=17/10=1 7/10
So, three half's plus one fifth is 1 7/10.
Your answer is 3.1. the way this is done is you find a number that both of the denominators can go into, in this case 10. multiply the 2 in 1/2 by 5, and the 5 in 1/5 by two. so now your problem should look some thing like this. 3 1/10 + 1/10. combine your 1/10's so you have 3 2/20. multiply 3x20+2 62/20, 3.1
